No, those boards are not "very sensitive" - actually the opposite is the case! I know MCUs, output pins of which have withstood a short connection to ground, the boards are protected electrically against ESD and are reasonably robust physically. The "sudden miscellaneous" behavior was most likely because of your firmware, using the ST-LINK Utility, which is not supported for those MCUs, something broken with CubeIDE or other software on your computer.
> So we are thinking that there is any internal issue with the board like missing libraries.
What libraries do you mean? For which software? For what purpose? Or are you just writing some fancy words from the internet to just sound "smart" and "professional" without an actual understanding of their meaning?
And you have not done "the best" even informing others about what exactly you did! The main post of the topic in general is almost an unintelligible gibberish. The word "blacklight" alone is a pure gold. Just think about it - black light - a thing that is literally impossible! And don't tell us that you don't know the difference of "back" vs "black". This just shows the level of attention to details...
So, was the board working before your "recovery"? Do you understand that the board has two MCUs? What did you do to the ST-LINK MCU? Did you erased it? What did you flashed to it? What is the current content of it's FLASH memory? Are you capable of telling what exactly did you do?
